Circulation: heart, cardiac cycle, ECG, double circulation, regulation, disorders
- Cardiac activities of the heart are regulated by :A. Nodal tissueB. A special neural centre in the medulla oblongataC. Adrenal medullary hormonesD. Adrenal cortical hormonesChoose the correct answer from the options given below : Answer: 1. A, B and C Only Key idea: The heart is regulated by nodal tissue (autorhythmic), the medullary cardiac centre (neural) and adrena... 1
- Match List I with List II :List I:A. P waveB. QRS complexC. T waveD. T-P gapList II:I. Heart muscles are electrically silent.II. Depolarisation of ventricles.III. Depolarisation of atria.IV. Repolarisation of ventricles.Choose the correct answer from… Answer: 3. A-III, B-II, C-IV, D-I Key idea: read the ECG waves. P wave - depolarisation of atria (A-III). QRS complex - depolarisation of ve... 1
- Following are the stages of pathway for conduction of an action potential through the heart:A. AV bundleB. Purkinje fibresC. AV nodeD. Bundle branchesE. SA nodeChoose the correct sequence of pathway from the options given below : Answer: 2. E-C-A-D-B Key idea: the impulse follows the heart's conducting system in a fixed order. SA node (pacemaker, E) → AV node (C) → AV... 1
- Match List I with List II.List I: A. P - wave; B. Q - wave; C. QRS complex; D. T - waveList II: I. Beginning of systole; II. Repolarisation of ventricles; III. Depolarisation of atria; IV. Depolarisation of ventriclesChoose the correct answer from th… Answer: 2. A-III, B-I, C-IV, D-II Key idea: Link each ECG wave to the heart event. P wave: depolarisation of the atria (III). Q wave: beginn... 1
- Which one of the following statements is correct ? Answer: 4. Blood moves freely from atrium to the ventricle during joint diastole. Key idea: During joint diastole, both atria and ventricles... 1
- The QRS complex in a standard ECG represents : Answer: 3. Depolarisation of ventricles In an ECG, the P wave is atrial depolarisation, the QRS complex is ventricular depolarisation (the s... 1
- What would be the heart rate of a person if the cardiac output is 5 L, blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL ? Answer: 3. 100 beats per minute Cardiac output = stroke volume × heart rate. Stroke volume =100-50=50 mL. Heart rate=5000 mL/min/50 mL/beat=... 1
- Match the Column - I with Column - II :Column - I | Column - II(a) P - wave | (i) Depolarisation of ventricles(b) QRS complex | (ii) Repolarisation of ventricles(c) T - wave | (iii) Coronary ischemia(d) Reduction in the size of T - wave | (iv) Depola… Answer: 1. (a) (iv) (b) (i) (c) (ii) (d) (iii) Link each ECG part to the cardiac event. P-wave: depolarisation of the atria, so (iv). QRS co... 1
- Match the items given in Column I with those in Column II and select the correct option given below :Column I | Column IIa. Tricuspid valve | i. Between left atrium and left ventricleb. Bicuspid valve | ii. Between right ventricle and pulmonary arter… Answer: 1. a-iii b-i c-ii Key idea: Valves keep blood flowing in one direction. Tricuspid valve: between right atrium and right ventricle (i... 1
- The hepatic portal vein drains blood to liver from : Answer: 3. Intestine Key idea: The hepatic portal vein carries nutrient-rich blood from the digestive organs to the liver. Of the options, t... 1
- Blood pressure in the pulmonary artery is : Answer: 3. more than that in the pulmonary vein. The pulmonary artery carries blood from the right ventricle at a pressure much higher than... 1